I don't know how to make it wrap onto a sphere without transitioning the whole project to 3D. Which is something I'd like to do, but will require a steep learning curve first.

The arc-like artifacts are intentional (which doesn't mean they're correct). I designed the fault lines to follow a sine curve with amplitude that varies from straight to about a half of an "S" shape. If this is wrong, what would be a more plausible shape to use?

I can definitely do offset mountains as I am calculating the slope on each side of the fault separately. Any idea on how often this feature should appear?

I'm working on improving the fractal seeding with a scaling factor and depth.

Thank you for your great comments!